1. Field of the Invention
The present invention relates to a display device and more particularly to a technology effectively applied to a display device which operates under high-temperature environment.
2. Background Art
TFT type liquid crystal display devices which use a thin film transistor as an active element have been used as a display device for a television set, a personal computer display, or the like because they can display a high-definition image. Particularly, small TFT type liquid crystal display devices have been frequently used as a display unit for a mobile-phone and an in-vehicle equipment.
A liquid crystal display device for in-vehicle use is required to start display under an environment at 95° C. In such a case, operation under an environment at 100° C. is required at a portion covered with a cover, such as a circuit component.
However, an IC used in a liquid crystal display device, particularly a control IC or the like used as a display control device does not ensure its operation at a temperature exceeding 100° C. Further, in the case of a logic IC, adjustment for reducing a rise in temperature due to voltage or current is also difficult.
Therefore, it is desired that a liquid crystal display device can operate even under high-temperature environment by suppressing a rise in temperature of a circuit component under high-temperature environment.
The invention has been made in view of the desire described above. It is an object of the invention to provide a display device which can operate even under high-temperature environment by suppressing a rise in temperature of a circuit component under high-temperature environment.
The above and other objects of the invention and the novel features thereof will be apparent from the description of the specification and the accompanying drawings.